Beautiful But Dangerous Invasive Alien Plants of Durban with some Indigenous Alternatives Beautiful But Dangerous Invasive Alien Plants of Durban and the Eastern, Sub-tropical Region of South Africa with some Indigenous Alternatives Durban Unicity Key Category 1 Category 2 Category 3 No Category Biocontrol Poisonous Herbicide Note: category numbers are shown on each panel Note: HERBICIDES may be used to control most plants, but this is only shown for those species for which chemicals have been registered. BIOCONTROL options are shown only for species where biocontrol is effective. Durban Unicity New Weed & Invader Plant Legislation By the year 2000, 10 million hectares of land in South Africa had been invaded by alien plants. Alien plants have numerous impacts: !They can increase flood damage. !They compete with agricultural crops. !They displace indigenous plants and animals. !They increase the loss of water from catchments. !They increase the severity of fires. !They expand the range of disease-causing organisms. Despite raising almost R 1 billion to date through national government programmes and working at unprecedented levels, we are not reducing the extent of the invasion. In recognising the threats posed by invasive plants, the national Department of Agriculture has drafted regulations and listed weeds and alien invader plants under the Conservation of Agricultural Resources Act. The list contains about 200 plants grouped into three categories: Weeds which may not be grown and must be controlled. Invader plants with commercial or utility value, which may only be grown with a permit under controlled circumstances. Invader plants, which have amenity value and which may be grown, but not plant- ed, propagated, imported or traded. You may not grow Category 3 plants within 30 metres of water- courses and the Department may instruct you to con- trol Category 3 plants in other areas. Category 1 Category 2 Category 3
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Beautiful But DangerousInvasive Alien Plants of Durban
with some Indigenous Alternatives
Beautiful But DangerousInvasive Alien Plants of Durban
and the Eastern, Sub-tropical Region of South Africa
with some Indigenous Alternatives
Durban Unicity
Key
Category 1
Category 2
Category 3
No Category
Biocontrol
Poisonous
Herbicide
Note: category numbers areshown on each panel
Note: HERBICIDES may beused to control mostplants, but this is onlyshown for those speciesfor which chemicalshave been registered. BIOCONTROL optionsare shown only forspecies where biocontrolis effective.
Durban Unicity
New Weed & Invader Plant Legislation
By the year 2000, 10 million hectares of land in SouthAfrica had been invaded by alien plants. Alien plantshave numerous impacts:
!They can increase flood damage.!They compete with agricultural crops.!They displace indigenous plants and animals.!They increase the loss of water from catchments.!They increase the severity of fires.!They expand the range of disease-causing organisms.
Despite raising almost R 1 billion to date throughnational government programmes and working atunprecedented levels, we are not reducing the extentof the invasion. In recognising the threats posed byinvasive plants, the national Department of Agriculturehas drafted regulations and listed weeds and alien
invader plants under the Conservation of AgriculturalResources Act.
The list contains about 200 plants grouped into threecategories:
Weeds which may not be grown andmust be controlled.
Invader plants with commercial or utilityvalue, which may only be grown with a
permit under controlled circumstances.
Invader plants, which have amenity valueand which may be grown, but not plant-
ed, propagated, imported or traded. You may notgrow Category 3 plants within 30 metres of water-courses and the Department may instruct you to con-trol Category 3 plants in other areas.
Category 1
Category 2
Category 3
This Poster’s Objective
Prevention of alien plant invasions is farcheaper than control or eradication.
This poster profiles some of the most aggres-sive weed and invader plants in the DurbanUnicity area. Another poster in the seriescovers problem plants that are often used inhorticulture.
The plants on this poster were selected usingthese criteria:!They have or are expected to invade largeparts of Durban and are likely to do so inother sub-tropical parts of South Africa.!They are potential transformers of naturalhabitats.
Control and Eradication
In practice a combination of mechanical, chemical andbiocontrol methods are used to combat alien plants.However, where infestations are light or cover relativelysmall areas, control is best achieved by mechanicalmeans. Tackle light infestations first and then denserinfestations.
Small plants may be pulled out at the roots especiallywhen the soil is moist. Larger plants may need to bedug out at the roots. The secret to success is to tacklethe job in a planned way and to diligently follow-up toremove seedlings and regrowth.
For more serious problems herbicides and/or biologicalcontrol, using natural predators or pests, may be used. Itis recommended that professional advice is soughtbefore using these methods.
Pearl Acacia (grey) and Triffid Weed (palegreen) stand out on a slope dominated by weeds.Each Triffid Weed plant produces over a millionseeds a year and the species is coastal KZN'sworst weed.
Water Hyacinth covers the water at Clairwood Quarry.Water Hyacinth can double its mass every 18 days aswell as produce over 5 000 long-lived seeds from eachflower spike.
South Africa has spent more than R 1 billion on nationalalien plant control and eradication programmes and isstill not reducing the extent of the problem.
Yellow Bells tree with saplings escaping cultiva-tion. A global survey of 1060 plant invasionsfound that in 59 % of the cases horticulture wasthe source.
For advice and planning of control work:! Plant Protection Research Institute, Cedara, runs a shortcourse on "Alien Plant Control for Land Managers". Tel: 033-355 9416 or 033-355 9413. E-mail: [email protected]! Your local District Conservation Officer, KZN Wildlife.Tel: 031-764 3515. E-mail: [email protected] ! The Ecological Advice Division, KZN Wildlife,Pietermartizburg. Tel: 033-845 1999.! Alien Buster Campaign, Toll-free line: 0800 005 376.
For information about the use of herbicides contact:! The Plant Protection Research Institute, Cedara. See abovefor details. Also http://www.nda.agric.za
For information about the use of biocontrol contact:! The Plant Protection Research Institute, Pretoria. Tel: 012-329 3269 or 012-329 3770.
E-mail: [email protected] find indigenous plants and professional contractorswho remove alien plants:! The Botanical Society - KZN Coastal Branch. Fax: 031-201 9958. E-mail: [email protected]! The Wildlife and Environment Society of South Africa(WESSA) - KZN Region. Tel: 031-201 3126. E-mail: [email protected]! Natural Areas Section, Durban Parks Department. Tel: 031-312 4466. E-mail: [email protected]! or visit these web sites:
For Law Enforcement:! National Department of Agriculture, Directorate: AgriculturalLand and Resource Management, Box 345, Pietermaritzburg,3200. Tel: 033-345 3515 or 033-345 3557.
Useful References! Botha, C. and Botha, J. Bring Nature Back to Your Garden. A
WESSA Handbook with a chapter on alien weeds and lots of sugges-tions for indigenous alternatives.
! Guiding Principles for the Landscaping of the Durban InnerCity and KwaZulu-Natal Coastal Belt. A Durban Metro publica-tion available from the cashier at the City Engineer’s Building, 166 OldFort Rd, Durban.
! Grobler, H et al. A guide to the Use of Herbicides. 17th edition.Available from the National Department of Agriculture, Directorate:Communication, Pvt Bag X144, Pretoria, 0001.
! Henderson, L. Alien Weeds and Invasive Plants. Published by thePlant Protection Research Institute of the Agricultural ResearchCouncil, Pretoria.
! Moore, J. Eradicating Invading Alien Plants in KwaZulu-Natal.This is a cheap and useful publication available from WESSA at 100 Brand Rd, Glenwood, Durban.
! Olckers, T. et al. Biological Control of Weeds in South Africa(1990-1998). African Entomology. Memoir No. 1. EntomologicalSociety of Southern Africa.
AcknowledgmentsThe production of this resource was a joint effort betweenthe Durban Unicity Environmental Management Branchand Parks Department, the Wildlife and EnvironmentSociety of SA, and the Botanical Society of SA.
With additional assistance from:
! Lesley Henderson of the Plant Protection Research Institute,Agricultural Research Council.
! Geoff Nichols, Richard Symmonds, Penny Croucamp and RichardBoon who supplied photographs.
Copies of this poster are available from:
! Durban Unicity Environmental Management Branch, Developmentand Planning Building, 166 Old Fort Rd, Durban. Tel: 031-3002517.
! Durban Botanic Gardens, Information Centre, 9A Sydenham Rd,Durban. Tel: 031-201 1303
! Wildlife and Environment Society of SA, 100 Brand Rd,Glenwood, Durban. Tel: 031-201 3126.